The present invention is related to an array-type modularized light-emitting diode structure and a method for packaging the structure. In the modularized light-emitting diode structure, multiple light-emitting diodes are arranged in an array.
FIG. 14 shows the packaging structure of a conventional light-emitting diode. The bottom electrode 61 of the light-emitting diode crystallite 6 is electrically adhered to a first metal electrode layer 62. The top electrode 61 of the light-emitting diode crystallite 6 via a conductive wire 66 is connected to another first metal electrode layer 62. The two first metal electrode layers 62 are both disposed on upper face 71 of a fiberglass substrate 7 and respectively connected to two second metal electrode layers 63 under lower face 73 of the fiberglass substrate 7 through perforations 72. Each light-emitting diode crystallite 6 is surrounded by a bowl-shaped reflective board 64 for focusing and upward reflecting the light emitted by the light-emitting diode crystallite 6. The bowl-shaped reflective board 64 is enclosed by a packaging resin layer 65 for protecting the light-emitting diode crystallite 6 and the conductive wire 66. Then the structure is cut along the center of the perforation 72.
When emitting light, the light-emitting diode will generate heat. Therefore, the lighting efficiency of the light-emitting diode is affected by the heat dissipating capability. The substrate 7 of the packaging structure of the conventional light-emitting diode is an insulator having poor heat dissipating capability. Moreover, the substrate 7 is enclosed by the first metal electrode layers 62 and second metal electrode layers 63. Therefore, it is hard for the heat generated by the light-emitting diode to dissipate from the substrate 7. The heat can only partially dissipate via the metal electrode layers 62, 63 exposed to outer side of the packaging resin layer 65. Therefore, the heat dissipation effect is very poor.
In order to solve the above problem, another type of packaging structure of light-emitting diode has been developed as shown in FIG. 15. A silicon chip serves as a substrate 8 which is formed with a depression 81 by means of exposure and development and wet etching. Then the bottom of the depression 81 is formed with two electrode guide through holes 82 by means of dry etching or laser. Then an insulating layer is formed on the surface of the substrate 8 by means of oxidization or nitrification. Then a metal layer is deposited on the insulating layer to form a metal electrode 811 and a reflective layer 812 in the depression 81 and form a back electrode layer 813 on the back face of the substrate 8. The metal electrode 811 in the depression is cut into positive and negative electrode faces by means of laser. Then, the light-emitting diode crystallite 9 is placed on the positive electrode face in the depression 81 and connected to the negative electrode face via a conductive wire 91. Then the depression 81 is point-packaged by resin. Finally, the structure is cut along a line between two depressions 81.
The substrate 8 is a silicon chip which has better heat dissipating effect. Moreover, the depression 81 in which the light-emitting diode crystallite 9 is placed is directly formed in the substrate 8 so that the heat generated by the light-emitting diode crystallite 9 can be directly dissipated from the substrate 8 to achieve better heat dissipating effect. However, the manufacturing procedure of such packaging structure of light-emitting diode is quite complicated. The surface of the substrate 8 must be first formed with the depression 81 by means of wet etching. Then the back face of the substrate 8 is formed with the electrode guide through holes 82 by means of dry etching or laser, which through holes 82 pass through the bottom of the depression 81. Then the insulating layer is formed on the surface of the substrate 8. Then the metal layer is deposited on the insulating layer to form the metal electrode and reflective layer in the depression. Then the metal electrode is cut into positive and negative electrode faces by means of laser. Especially, when making the electrode guide through holes 82, it is necessary to form the electrode guide through holes 82 of the depressions 81 one by one. Mass-production is impossible so that the manufacturing cost is greatly increased.
Furthermore, the above packaging structures of the light-emitting diode are mainly used to manufacture single light-emitting diode. Such packaging structures are not applicable to array-type modularized structure. In array-type light-emitting diodes, the entire layout and convenience in electric connection with outer side must be considered. The above packaging structures of light-emitting diode both lack layout design adapted to modularization. Therefore, it is impossible to manufacture array-type modularized structure.